Burstyn Group
Bioinorganic Chemistry at the University of Wisconsin
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Research
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The Burstyn Group is divided into two subgroups. The more biologically-orientated "heme" subgroup focuses on the biochemical and biophysical characterization of three heme-containing proteins and enzymes, while the synthetically-orientated "ethylene" subgroup is focused on modeling and applying the ethylene-sensing chemistry of the ETR1 receptor in plants. |
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Heme Subgroup | |
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Heme proteins serve as sensors
and signal transducers in a number of important biological processes. For
example, NO regulates your blood pressure by interacting with the enzyme
soluble guanylyl cyclase
(sGC). Bacteria use heme proteins to sense gases such as dioxygen, CO, and NO
in their environment. In our laboratory, research efforts are directed towards
understanding how gas sensing occurs at the metal center, and how changes in the
coordination chemistry at the metal center are coupled to allosteric
conformational changes in the protein. Through our studies of the mammalian
NO-sensor sGC and the bacterial CO sensor
CooA, we have learned
that interaction of the gas molecules with the heme centers induces changes in
the coordination geometry, and these changes correlate with functional changes
in the proteins. Our current work aims to elucidate the mechanisms by which the
coordination changes are communicated through the protein. In addition we are
using knowledge gained in the study of sGC and CooA to investigate whether the
heme group in the enzyme
cystathionine
β-synthase
(CBS) serves as a sensor. In these studies we utilize a variety of biochemical
and biophysical tools, including enzyme kinetics, protein modification or
mutagenesis, electronic absorption, EPR, resonance Raman, circular dichroism,
magnetic circular dichroism, and fluorescence spectroscopies, to probe the
structure-function relationships in these proteins. | |
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Ethylene Subgroup | |
| Ethylene is an essential hormone in all plants for the control of growth and maturation and is another important gaseous signaling agent. Ripening of fruit is an example of an ethylene-dependent process and one of great interest to the fruit and vegetable industry. Although it has been speculated for years than a metal, most often copper, may be involved in ethylene-mediated signaling, the proteins involved in the ethylene response have been extraordinarily difficult to isolate. We are studying Cu(I)-ethylene complexes bearing auxiliary nitrogen and sulfur donor ligands, in order to understand how ethylene may bind to the ethylene receptor protein. | |
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